Antimicrobial activity of daptomycin and selected comparators tested against bloodstream Staphylococcus aureus isolates from hemodialysis patients.
BACKGROUND
Patients on long-term hemodialysis are at a significantly higher risk for catheter-related bloodstream infections (BSI) than the general population. These infections are generally caused by gram-positive organisms, especially Staphylococcus aureus. In the present study, we evaluated the antimicrobial susceptibility patterns of S. aureus causing BSI in dialysis patients compared to those causing BSI in other patient populations.


METHODS
The potencies of daptomycin and various comparator agents were evaluated by reference broth microdilution methods for S. aureus bloodstream isolates from dialysis patients (606 strains) in 43 hospitals in North America and Europe. Susceptibility patterns for the dialysis isolate set were compared to those S. aureus causing BSI in other patient populations in the same hospitals and time period.


RESULTS
Daptomycin was highly potent against S. aureus causing bacteremia in dialysis patients (MIC(50)/MIC(90), 0.25/0.5 microg/ml). Vancomycin (MIC(50)/MIC(90), 1/1 microg/ml) and linezolid (MIC(50)/MIC(90), 2/2 microg/ml) showed similar potency, and overall susceptibility rates for the three antibiotics were 99.8-100.0% susceptible. Linezolid and vancomycin were four- to eight-fold less potent than daptomycin.


CONCLUSIONS
The overall susceptibility patterns of S. aureus strains from dialysis patients were very similar to those of non-dialysis patients.
Sader
Helio S
HS
JMI Laboratories, 345 Beaver Kreek Centre, Suite A, North Liberty, Iowa 52317, USA. helio-sader@jmilabs.com
Fritsche
Thomas R
TR
Jones
Ronald N
RN
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D016470:Bacteremia / Q000382:microbiology*; D017576:Daptomycin / Q000494:pharmacology*; D005060:Europe; D006801:Humans; D008826:Microbial Sensitivity Tests; D009656:North America; D006435:Renal Dialysis / Q000009:adverse effects*; D013203:Staphylococcal Infections / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification
D000900:Anti-Bacterial Agents; D017576:Daptomycin